Eyewitnesses described windows smashing and flames surging through until the roof was alight.

Residents said they saw a man wearing boxer shorts and carrying a knife running from the house before being calmed down by a neighbour.

Teenagers Tia Richardson and Coral Spence alerted the fire brigade and knocked on people’s doors to get local families to safety. A man has been arrested and yesterday an arson investigation team were searching for clues at the flats to find out how it started.

Tia, 15, spotted the blaze as she and a friend took the dog for a walk at about 11pm on Tuesday.

She said: ‘We saw the smoke and thought it was a bonfire.

‘As I walked forward, I could see the flats were on fire.

‘The windows smashed and the flames were coming out of the roof. It was horrible.

‘We ran and knocked on people’s doors to help get everyone out.’

Coral, 14, was inside the house and dialled 999 when she saw the smoke.

She said: ‘I was on the phone explaining everything and then I saw someone run out in their boxers with a knife.

‘He went round towards the car park and then stopped. The fire was getting worse.’